Alexander Lebedev, the Russian oligarch, has accused a group of spies and policemen of plotting to steal his multi-billion pound business empire in an open letter to Vladimir Putin, the prime minister.

Alexander Lebedev said he had been asked to pay seven-figure bribes to stop the harassment Photo: BLOOMBERG NEWS

The 50-year-old owner of The Independent newspaper titles and the London Evening Standard said his Moscow-based banking empire was under serious attack and that he had been threatened with jail unless he left the country.

"Thank God there have been no grenades or plastic explosives so far," he wrote.

"(But) we are dealing with an organised mafia group acting on the pretext that it is "carrying out orders from above."

With an estimated £1.9 billion to his name, Mr Lebedev is thought to be the 40th richest man in Russia controlling a sprawling banking empire which has assets in the airline, housing, and agricultural sectors as well as shares in Novaya Gazeta, a famous liberal opposition newspaper.

But Mr Lebedev said a gang of corrupt FSB secret service agents and policemen were trying to take it all away from him in an elaborate criminal conspiracy tied to a small bank he used to control. The same gang had already perfected their scheme to steal "a minimum of" £3.1 billion in similar raids in the past, he claimed.

Last November, the Moscow offices of Mr Lebedev's National Reserve Bank were raided by dozens of armed investigators in what he believes was an attempt to scare him into capitulating to the plotters.

"Respected Vladimir Vladimirovich (Putin)! I am requesting you intervene in the situation, (and sort out) the bandit raid by werewolves in epaulettes," Mr Lebedev wrote, using a derogatory term for corrupt law enforcement officers.

He said he had been asked to pay seven-figure bribes to stop the harassment and that there had been fifty attempts to frighten his employees and relatives in December and January alone.

Earlier this week, he pulled out of a business conference in London, saying he feared he might not be let back into Russia if he went. Mr Lebedev occupies an ambiguous position in Russian life. A former KGB spy who once worked at the Soviet embassy in London, he has often spoken out against corruption and abuse of government power but has been careful to avoid directly criticising Mr Putin or President Dmitry Medvedev.

In a separate case, French authorities moved on Friday to seize two yachts worth an estimated £12.5 million and other possessions allegedly belonging to UK-based Russian oligarch Boris Berezovsky acting on the request of the Russian authorities who are conducting a criminal investigation into him.

Mr Berezovsky denied he owned any yachts moored in France but confirmed he had other possessions such as paintings. He had not been to France for about a decade, he added.